text: This paper gives an overview about enzyme catalysis, and reports the precision synthesis of multifunctional poly(ethylene glycol)s using this green chemistry approach. Specifically, vinyl acrylate was transesterified with tetraethylene glycol (TEG) and a PEG with DPn = 23, and then (HO)2–TEG–(OH)2 and (HO)2–PEG–(OH)2 were synthesized by the Michael addition of diethanolamine to the acrylate double bonds. These structures will serve as the core of novel dendrimers designed for drug delivery applications.